Various materials have been suggested for imparting a flame retardant characteristic or property to combustible materials. Phosphorinanes are described in German Patent Application Nos. 2,146,988 and 2,327,185 as well as Swiss Patent Nos. 533,718 and 542,953. U.S. Pat. No. 3,456,041 teaches the use of phosphites and phosphonates of brominated pentaerythritol. U.S. Pat. No. 3,642,944 teaches fire retardant polyesters employing as a reactant dibromoneopentyl glycol. U.S.Pat. No. 3,324,205 teaches the use of halogenated phosphates and phosphonates as useful for flame retardant compositions. See also U.S. Pat. No. 2,828,288 for early disclosure of flame retardant compositions.